Description of the Prior Art
The desirability for controllably orienting an object in three dimensions, namely rotation about an axis and inclination with respect to that axis, and tilting of the axis itself, has long been recognized in various diverse fields of endeavor. These fields of endeavor include astronomy, antenna control, spacecraft attitude control, microscopy, photography, and construction of various flexible work platforms. Numerous United States and foreign patents have addressed the problems associated with control of an objects orientation. Noteworthy among the United States patents are U.S. Pat. No. 5,573,218, issued in 1996 and U.S. Pat. No. 4,819,002, issued in 1989.
The prior art devices have focused on providing orientation of an object in three dimensions, whereas the present invention addresses problems specifically related to orienting an object in two dimensions, namely rotation about an axis and inclination with respect to that axis. The problem with the prior art devices is that they have not met all of the desired features for a device which is optimized to control the orientation of an object in the above two dimensions. Principal among these features is the ability for the object to be rotated continuously about an axis. Prior art devices typically rotate the object by means of electric motors located within the rotating mounting structures. This limits rotation to the length and twisting capabilities of the electrical connections. The present invention locates all rotating and inclination actuators outside of the rotating mounting structures, thus permitting continuous rotation. Another desired feature not adequately addressed by the prior art is ability of the device to maintain an accurate rotational orientation while effecting a inclination of the object. Prior art devices achieve this type of control through complex feedback circuitry or similar means while the present invention solves this problem through simple mechanical linkage.
In addition, as most prior art devices provide three dimensional control for the orientation of an object, they are necessarily more complex, difficult and expensive to manufacture and more complex for the user to control. The present invention successfully addresses all of these issues while prior art devices have failed adequately to meet one or more of the above described desirable features.